Presently those mini-bulbs or small bulbs of the prior art may not be able to converge the light emitting therefrom because the head portions thereof are in the cone or column shapes. Consequently, not only their luminosity is lowered and the light emitted from the filament is not sufficiently utilized, but also the patterns formed by the rays emitted from the bulb are simple and create no aesthetic feelings. Furthermore, it cannot form an eye-shaped halo pattern.